This invention relates to determining the level of a nongaseous substance in a chamber. More particularly, this disclosure pertains to a hand-held, two-arm, caliper-like portable level detector having a gamma radiation source on one arm and a scintillator on the other arm.
There are many times when it is desirable to measure the level of a liquid in a cylinder, for example, the level of the fire extinguishing liquid Halon. The measurement should be made without disrupting service lines to the chamber and without opening the chamber. It is also desirable that the measuring system be suited for use on cylinders of different sizes. Neutron and gamma ray backscatter gauges have been developed which require only one access surface on the wall of the container; but these backscatter gauges do not provide satisfactory contrast between some liquids and their surroundings.